The more you know

Oh shit, she might be me

That always happens to me, but not the other way around

What if it’s justified?

It usually occurs through association and so after awhile it feels more like a survival thing, that if you don't be happy then the threat will never occur. It's irrational but like most phobia's, fear is strong motivator for behaviour. I encourage anyone who feels this way to keep pushing themselves, your happiness is valid and you should let yourself feel happiness, it's really hard when you're anxious you'll be "punished" for this happiness but keep trying.